The Double Star magnetic field investigation: Overview of instrument performance and initial results

Abstract. One of the primary objectives of the Double Star mission is the accurate measurement of the magnetic field vector along the orbits of the two spacecraft. The magnetic field is an essential parameter for the understanding of space plasma processes and is also required for the effective interpretation of data from the other instruments on the spacecraft. We present the design of the magnetic field instrument onboard both of the Double Star spacecraft and an overview of the performance as measured first on-ground and then in-orbit. We also report the results of in-flight calibration of the magnetometers, and the processing methods employed to produce the final data products which are provided to Double Star investigators, and the wider community in general. Particular attention is paid to the techniques developed for removing magnetic interference generated by the solar arrays on the first (equatorial orbiting) spacecraft. Results from the first year of operations are reviewed in the context of combined observations by Double Star and Cluster, and examples given from the different regions visited by the spacecraft to date.

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Radial variation of whistler-mode chorus: first results from the STAFF/DWP instrument on board the Double Star TC-1 spacecraft

Annales Geophysicae ◽

10.5194/angeo-23-2937-2005 ◽

2005 ◽

Vol 23 (8) ◽

pp. 2937-2942 ◽

Cited By ~ 45

Author(s):

O. Santolík ◽

E. Macúšová ◽

K. H. Yearby ◽

N. Cornilleau-Wehrlin ◽

H. StC. K. Alleyne

Keyword(s):

Cyclotron Frequency ◽

Power Spectra ◽

Double Star ◽

Electron Cyclotron ◽

Radial Variation ◽

Whistler Mode ◽

Electron Cyclotron Frequency ◽

The Earth ◽

First Results ◽

Initial Results

Abstract. We use the first measurements of the STAFF/DWP instrument on the Double Star TC-1 spacecraft to investigate whistler-mode chorus. We present initial results of a systematic study on radial variation of dawn chorus. The chorus events show an increased intensity at L parameter above 6. This is important for the possible explanation of intensifications of chorus, which were previously observed closer to the Earth at higher latitudes. Our results also indicate that the upper band of chorus at frequencies above one-half of the electron cyclotron frequency disappears for L above 8. The lower band of chorus is observed at frequencies below 0.4 of the electron cyclotron frequency up to L of 11-12. The maxima of the chorus power spectra are found at slightly lower frequencies compared to previous studies. We do not observe any distinct evolution of the position of the chorus frequency band as a function of L. More data of the TC-1 spacecraft are needed to verify these initial results and to increase the MLT coverage.

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Direct Determination of the Velocity of Vortices in High-Tc Superconductors by a Non-Equilibrium Method

International Journal of Modern Physics B ◽

10.1142/s0217979298002489 ◽

1998 ◽

Vol 12 (29n31) ◽

pp. 3288-3291

Author(s):

I. Kirschner ◽

R. Laiho ◽

A. C. Bódi ◽

E. Lähderanta ◽

I. Vajda

Keyword(s):

Magnetic Field ◽

Temperature Gradient ◽

Vortex Motion ◽

Direct Determination ◽

Field Investigation ◽

High Tc Superconductors ◽

High Tc ◽

Pinning Centers ◽

Non Equilibrium

As is shown, thermally assisted vortex motion can come into being in high-T c superconductors due to the applied temperature gradient. Its behavior strongly depends on the local and global microstructure of the samples, moreover on the temperature and magnetic field. Investigation of the density, size and intensity of the pinning centers of specimens leads to the conclusion that the higher homogeneity immediately weakens and the lower one strenghtens the pinning, thus the former promotes and the latter impedes the vortex motion. The non-equilibrium experimental technique together with a.c. susceptibility measurements render possible the direct determination of the velocity of vortices. Depending on the actual microstructural state of samples it has the values between 6 × 10-2 mm/s and 18 × 10-2 mm/s in the case of Y-Ba-Cu-O specimens investigated.

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The fluxgate magnetometer of the Low Orbit Pearl Satellites (LOPS): overview of in-flight performance and initial results

Geoscientific Instrumentation Methods and Data Systems ◽

10.5194/gi-10-227-2021 ◽

2021 ◽

Vol 10 (2) ◽

pp. 227-243

Author(s):

Ye Zhu ◽

Aimin Du ◽

Hao Luo ◽

Donghai Qiao ◽

Ying Zhang ◽

...

Keyword(s):

Magnetic Field ◽

Current System ◽

Field Measurements ◽

Stray Field ◽

Fluxgate Magnetometer ◽

General Description ◽

Flight Performance ◽

Spatial Coverage ◽

Magnetic Field Measurements ◽

Initial Results

Abstract. The Low Orbit Pearl Satellite series consists of six constellations, with each constellation consisting of three identical microsatellites that line up just like a string of pearls. The first constellation of three satellites were launched on 29 September 2017, with an inclination of ∼ 35.5∘ and ∼ 600 km altitude. Each satellite is equipped with three identical fluxgate magnetometers that measure the in situ magnetic field and its low-frequency fluctuations in the Earth's low-altitude orbit. The triple sensor configuration enables separation of stray field effects generated by the spacecraft from the ambient magnetic field (e.g., Zhang et al., 2006). This paper gives a general description of the magnetometer including the instrument design, calibration before launch, in-flight calibration, in-flight performance, and initial results. Unprecedented spatial coverage resolution of the magnetic field measurements allow for the investigation of the dynamic processes and electric currents of the ionosphere and magnetosphere, especially for the ring current and equatorial electrojet during both quiet geomagnetic conditions and storms. Magnetic field measurements from LOPS could be important for studying the method to separate their contributions of the Magnetosphere-Ionosphere (M-I) current system.

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The Cluster Magnetic Field Investigation

The Cluster and Phoenix Missions ◽

10.1007/978-94-011-5666-0_3 ◽

1997 ◽

pp. 65-91 ◽

Cited By ~ 24

Author(s):

A. Balogh ◽

◽

M. W. Dunlop ◽

S. W. H. Cowley ◽

D. J. Southwood ◽

...

Keyword(s):

Magnetic Field ◽

Field Investigation

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Observation of reconnection pulses by Cluster and Double Star

Annales Geophysicae ◽

10.5194/angeo-23-2921-2005 ◽

2005 ◽

Vol 23 (8) ◽

pp. 2921-2927 ◽

Cited By ~ 1

Author(s):

X. H. Deng ◽

R. X. Tang ◽

R. Nakamura ◽

W. Baumjohann ◽

T. L. Zhang ◽

...

Keyword(s):

Magnetic Field ◽

Energetic Electron ◽

Curvature Vector ◽

Double Star ◽

Neutral Sheet ◽

Inner Magnetosphere ◽

Point Analysis ◽

Earthward Flow ◽

Tailward Flow ◽

The Magnetic Field

Abstract. During a reconnection event on 7 August 2004, Cluster and Double Star (TC-1) were near the neutral sheet and simultaneously detected the signatures of the reconnection pulses. AT 22:59 UT tailward flow followed by earthward flow was detected by Cluster at about 15 RE, while earthward plasma flow followed by tailward flow was observed by TC-1 at about 10 RE. During the flow reversal from tailward to earthward, the magnetic field Bz changed sign from mainly negative values to positive, and the X component of the magnetic curvature vector switched sign from the tailward direction to the earthward direction, which indicates that the reconnection site (X-line) moved tailward past the Cluster constellation. By using multi-point analysis and observation of energetic electron and ion flux, we study the movement and structure of the current sheet and discuss the braking effect of the earthward flow bursts in the inner magnetosphere.

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